Albuterol

Indications

Albuterol is used for the treatment and prevention of bronchospasm (acute or severe) in patients with reversible obstructive airway disease. It is also indicated for the prevention of exercise-induced bronchospasm.[1][2][3]

Mechanism of Action

Albuterol acts on beta2-receptors to relax the bronchial smooth muscle. It also inhibits the release of immediate hypersensitivity mediators from cells, especially mast cells. Although albuterol affects beta1-receptors, this is minimal and has little effect on the heart rate.[4][5]

Administration

Albuterol comes in a variety of dosing forms and strengths. An aerosol metered-dose inhaler gives 90 mcg (base)/actuation, which is equivalent to 108 mcg of albuterol sulfate. The powder metered-dose inhaler form gives the same values as the aerosol metered-dose inhaler. Albuterol also is offered in 2 mg and 4 mg tablets. Extended-release tablets are available in 4 mg and 6 mg versions. As a nebulized solution, albuterol is offered in 0.083%, 0.5%, 0.63 mg/3mL, and 1.25 mg/3 mL forms. There is also a syrup that is available that is offered in a 2 mg/5 mL solution.[6]

Several forms of treatment for bronchospasm have been accepted as proper. A nebulized solution of 2.5 mg two or three times a day as needed is acceptable for quick relief of symptoms. A dosing of 1.25 to 5 mg every four to eight hours as needed of the nebulized solution is also effective for quick relief of symptoms. For the powdered and aerosol metered-dose inhaler, it is advised to use one or two puffs of 90 mcg every four to six hours depending on the patient, but it is advised not to exceed 12 puffs within 24 hours. For tablet and syrup formulations, 2 to 4 mg every 6 to 8 hours is recommended with the advisory to not exceed 32 mg in one day. The extended-release tablets are taken in either 4 mg or 8 mg doses (depending on the patient’s need) every 12 hours with the limit of 32 mg per day.[7]

For the treatment of acute or severe bronchospasm, it is advised to use a nebulizer solution with a concentration of 2.5-5 mg every 20 minutes for three cycles. This should be followed by repeat nebulizer treatments of 2.5-10 mg every 1-4 hours as needed. Treatment can be maintained with continuous nebulizer treatments every 10-15 minutes. If treating with a metered-dose inhaler, 4-8 puffs of 90mcg every 20 minutes for up to 4 hours is standard practice followed by 4-8 puffs every 1-4 hours as needed.

For exercise-induced bronchospasm, it is advised to treat with aerosol or powder metered-dose inhaler prior to exercise. 2 puffs of 90mcg (for a total of 180mcg) taken 15-20 minutes prior to exercise may help prevent symptoms.

For the treatment of pediatric patients, age becomes a big factor in our course of treatment. For children under two years old, nebulizer solution with dosing by weight of 0.2-0.6 mg/kg/day divided into either a 4 or 6-hour cycle. For children two years old and older, a nebulizer solution dosing of the 2.5mg/0.5mL solution is given every 6-8 hours with a maximum of 10 mg given in any 24-hour period.

The use of aerosol metered-dose inhalers in the pediatric population under the age of 4 years old has not been studied. Dosing recommendation for four years and older to take 90-180mcg (1-2 puffs) every 4-6 hours.

The use of powder metered-dose inhalers in the pediatric population under the age of 4 years old has not been studied. Dosing recommendation for four years and older to take 180mcg (2 puffs) every 4-6 hours not to exceed 12 puffs within a 24-hour period.[2]

The dosing of albuterol tablets in pediatric patients under six years old is 0.3-0.6 mg/kg/day divided into three treatments given every 8 hours throughout the day. It is advised not to exceed 12 mg/day. For those ages 6-12, 2 mg every 6-8 hours is advised with the daily maximum of 24 mg per day. For pediatric patients over the age of 12, 2-4 mg given every 6-8 hours with the daily maximum of 32 mg.[8]

Extended-release albuterol tablets are not advised for those under the age of 6. For pediatric patients between 6 and 12 years of age, it is recommended that a dosing of 4 mg every 12 hours is given, not to exceed 24 mg in a 24-hour period. For pediatric patients over the age of 12, 8 mg taken every 12 hours is the recommended dose.

The syrup formulation has not been studied in children under the age of 2. For patients between the ages of 2 and 6, 0.1 mg/kg should be given every 8 hours. This can be increased if needed to 0.2 mg/kg if needed every 8 hours. For those 6 to 14 years of age, 2 mg taken every 6 to 8 hours should suffice. For pediatric patients over the age of 14, 2 to 4 mg taken every 6 to 8 hours is recommended with a daily maximum of 32 mg/day.

Adverse Effects

The primary adverse effects of albuterol therapy are tremors and nervousness, mostly seen in children who are 2 to 6 years of age. These side effects occur in approximately one in every five patients. Other side effects include insomnia and nausea, which occur in approximately 1 in every ten patients. Less common adverse effects may include fever, bronchospasm, vomiting, headache, dizziness, cough, allergic reactions, otitis media, epistaxis, increased appetite, urinary tract infections, dry mouth, gas, hyperhidrosis, pain, dyspepsia, hyperactivity, chills, lymphadenopathy, ocular pruritus, sweating, conjunctivitis, and dysphonia. Albuterol also has been shown to increase blood pressure and may cause hypokalemia. Increased blood glucose level and prolonged QT interval and ST segment depression have been noted, although rare.[9][10]

Contraindications

Hypersensitivity is a contraindication for albuterol. Also, if a patient is severely hypersensitive to milk protein, it is advised to avoid the use of albuterol.

Monitoring

Monitoring parameters for albuterol include forced expiratory volume, peak flow, blood pressure, heart rate, Central nervous system stimulation, serum potassium, serum glucose, and asthma symptoms. Since paradoxical bronchospasm may occur, it is important to advise patients to discontinue use and seek medical attention if symptomology worsens with use. If more doses are needed over time, alterations may be needed to the patient’s current treatment regiment as the patient's condition may have deteriorated or asthma may have progressed to seizures.[11]

Toxicity

A dose of 1 mg/kg is potentially toxic in the pediatric population under the age of six.

Enhancing Healthcare Team Outcomes

All healthcare workers including nurse practitioners who prescribe inhalers should educate the patients on how to use these medications. It is essential to use a face mask in children under the age of 4. Caution should be taken when treating patients with a cardiovascular disease, such as heart disease, as albuterol may exacerbate heart failure with reduced ejection fraction. It is also important to monitor patients closely with diabetes, hyperthyroidism, hypokalemia, glaucoma, or history.[12]